Dirction / Step lines!

[bigal]

Hi, i am trying to build a new controller for a small dead CNC mill at my school. It is a old mill with basic steppers and limit switches, so i am planning on using the TurboCNC program and its circuit "U-2 Stepper Translator IC"

Here

Here is my I/O line setup:

2: A Step
3: A Direction
4: B Step
5: B Direction
6: C Step
7: C Direction
8: Spindle ON
9: Coolent / spare

10: Limit X
11: Limit Y
12: Limit Z
13: STOP

Now, my questions are:

For the limits, do you just push the 5v logic you are using for the power to the Pics into the pins on the parallel port? Or do you have to put resistors in place on the 5v to them? Also, the sheet for the available functions for the output pins has no direction / step functions?

I/O Points Point Usage Spindle Power (Output) Drives relay that turns spindle motor on and off. Could also drive spindle brake. Spindle Direction (Output) Drives relay that sets spindle direction to clockwise or counter clockwise. Coolant A (Output) Drives relay that controls flood coolant pump Coolant B (Output) Drives relay that controls mist coolant pump PLC Handshake Signal (Output) Signal controlled by M70 and M71 to provide programmatic interface to a Programmable Logic Controller or other electronics Drive Enable 1 (Output) Used to enable or disable one or more motor drives. Since some motor drives require individual enable lines, TurboCNC provides three independent lines which are controlled by the same M17/M18 Drive Enable 2 (Output) Used to enable or disable one or more motor drives. Since some motor drives require individual enable lines, TurboCNC provides three independent lines which are controlled by the same M17/M18 Drive Enable 3 (Output) Used to enable or disable one or more motor drives. Since some motor drives require individual enable lines, TurboCNC provides three independent lines which are controlled by the same M17/M18 Clamp Selector Bit 0 (Output) – used with Bits 1, 2, 3 to specify which clamp is to be controlled. Clamp Selector Bit 1 (Output) – used with Bits 0, 2, 3 to specify which clamp is to be controlled. Clamp Selector Bit 2 (Output) – used with Bits 0, 1, 3 to specify which clamp is to be controlled. Clamp Selector Bit 3 (Output) – used with Bits 0, 1, 2 to specify which clamp is to be controlled. Clamp Motor On Signal (Output) drives clamp controller specified by Clamp Selector Bits 0-3. Clamp Direction Closed (Output) Tool Turret Index (Output) Toggles 1 times the tool number of pulses when an M06 instruction is executed. Collet Open Solenoid (Output) drives mechanism to open the tool holder, which may be a collet Collet Close Solenoid (Output) drives mechanism to close the tool holder, which may be a collet Emergency Stop (Input) when activated, this line causes the CNC machine to stop operation. Limit Switch 1 (Input) Is activated when Axis #1 reaches either limit of its travel. Limit Switch 2 (Input) Is activated when Axis #2 reaches either limit of its travel Limit Switch 3 (Input) is activated when Axis #3 reaches either limit of its travel PLC Handshake Sense (Input) Used to synchronize the CNC machine to a Programmable Logic Controller or other electronic device. Spindle Index (Input) Used to synchronize lathe’s lead screw to spindle for gearless thread cutting. Can also be used to calculate and display spindle speed. Spindle Encoder A (Input) Not currently used Spindle Encoder B (Input) Not currently used Touch Probe (Input) Stops motion on a G31/32 or probe move in jog mode. Often used for digitizing part data or toolsetting. Jog Encoder A (Input) Quadrature channel A of a jogging encoder wheel. In discrete jog mode, this is an input to move an axis. Jog Encoder B (Input) Quadrature channel B of a jogging encoder wheel. In discrete jog mode, this is an input to move an axis. Block Hold (Input) When active, TurboCNC will not execute the next block in the CNC program. Could be used as a single step control. Start Inhibit (Input) When active, TurboCNC will not start executing a CNC program. Could be used to allow a raw materials handler to remove completed part from machine and insert new raw material. Clamp Sense Opened (Input) line which is activated when the clamp specified by the Clamp Select bits is opened Clamp Sense Closed (Input) line which is activated when the clamp specified by the Clamp Select bits is closed Home Switch 1 (Input) Senses when Axis #1 is at home position Home Switch 2 (Input) Senses when Axis #2 is at home position Home Switch 3 (Input) Senses when Axis #3 is at home position Home Switch 4 (Input) Senses when Axis #4 is at home position Home Switch 5 (Input) Senses when Axis #5 is at home position Home Switch 6 (Input) Senses when Axis #6 is at home position Home Switch 7 (Input) Senses when Axis #7 is at home position Home Switch 8 (Input) Senses when Axis #8 is at home position

cheers,
Alex

[fyffe555]

Alex, sounds like a good project. Wish we'd had a cnc mill when I was at school.

Couple of points; The pic U2 stepper from Dave @ DAK is for unipolar stepper wiring. Make sure you can wire the steppers you have as unipolar. It would be worth looking at the open source and electronics sections here as there are several other drivers that might work for you too.

Are you using a breakout board?

For limit switches are your switches normally open or normally closed? If you set that for the appropriate pin in TCNC ( lo or hi) then you can often wire the switch directly to the port earth (18-25) and the pin input. If the switches are normally open, which is usually the best, then you might need to pull the pin up to 5v with a resistor, with the switch taking it low when closed.

The setup for the step direction pins is in the Axis setup, not the IO section that you've listed here..

Andrew

[bigal]

unipolar being where you have 4 grounds and a live and it twitches round a bit each time you touch a ground wire to ground? what are the alternitives? Havent looked yet, will have to take the machine apart some more... its in the tech department at school, so will have to steal a motor off it for testing!